Tractors such as track-type tractors are used in a great many different operations, ranging from pushing loose material or debris about a worksite to grading, production dozing or scraping where materials are dug from a substrate, and still other applications related to site preparation, forestry, mining, and general civil engineering. Track-type tractors offer the advantage of a rugged build and substantial capacity for drawbar pull and traction in challenging underfoot conditions, steep terrain, and when towing or pushing large loads.
Due to the nature of the service environment within which track-type tractors operate, the tracks typically experience some slip relative to the underlying substrate. It has been discovered that the extent of track slip in relation to drawbar pull affects operating efficiency of the track-type tractor. If a track-type tractor is experiencing close to 100% track slip, then the track-type tractor is not presently traveling and therefore not likely moving any material or otherwise performing any useful work. On the other hand, if the track-type tractor is experiencing close to 0% track slip the track-type tractor may be traveling but is likely not moving any load apart from the tractor's own weight. Along a so-called pull-slip curve between 100% slip and 0% slip there is a window or zone of greatest efficiency. Different pull-slip curves may be applied to different machine conditions or different service conditions, with the idea that certain machine or operating parameters can be varied in real time to cause the track-type tractor to operate as efficiently as is practicable. U.S. Pat. No. 8,983,739 to Faivre discloses real-time pull-slip curve modeling based upon information as to soil conditions. Establishing an accurate, real-time pull-slip curve theoretically enables an operator or autonomous controller to vary machine parameters, such as track speed, more effectively to achieve efficiency or other aims. Despite advancements taught by Faivre and others, there remains ample room for advancement in controls technology for track-type tractors and related implements.